A mobile terminal is a communication device which permits mobile communication with another party. Mobile terminals are capable of voice communication, sending and receiving text messages, accessing the Internet, receiving television signals, and capturing still and video images and sending the captured images to the other party. Mobile terminals may have various types of construction, such as a top sliding type, a folder type, a flip type, and a bar type.
FIG. 1 is a perspective view illustrating a top sliding type mobile terminal. FIG. 2 is an exploded view illustrating the top sliding type mobile terminal. FIG. 3 is a perspective view illustrating operation of the top sliding type mobile terminal.
Referring to FIG. 1, the mobile terminal includes a body 100 having a lower portion that includes a keypad 110. The mobile terminal also includes a slider 200 configured to slidingly couple to the body 100. The mobile terminal also includes a longitudinal sliding unit coupled between the slider 200 and the body 100 such that the slider 200 may move longitudinally with respect to the body 100. The mobile terminal also includes a display unit 210 fixedly coupled to the slider 200.
The body 100 may be constructed in a rectangle shape and have a certain thickness. A keypad 110 has a plurality of keys 111 and is placed in the body 100 such that the keys 111 may protrude outside of the body 100. However, the number of the keys 111 may be decreased because of limitations on the size of the area where the keys 111 are arranged. Therefore, each of the keys 111 may have both a function of entering numbers and a function of entering letters. That is, the primary function of the keys 111 is to enter numbers, but each of the keys 111 may also be used to enter a plurality of letters. Therefore, to input a message, the same key 111 may need to be pressed several times to input different letters.
When in a first position, the slider 200 is placed on top of the body 100 such that the keys 111 are covered by the slider 200. When the slider 200 is moved in a longitudinal direction with respect to the body 100, the keys 111 are exposed to provide access to the keys 111 for a user. Furthermore, a battery 120 is detachably mounted on the lower surface of the body 100.
A display unit 210 is provided on an outer surface of the slider 200. An operating keypad 220 is provided on the outer surface of the slider 200, below the display unit. Voice phone calls are made and terminated by pressing keys 221 on the operating keypad 220. A display window 211 of the display unit 210 is rectangular in shape and is oriented in the same longitudinal direction as the slider 200.
Referring to FIG. 2, the longitudinal sliding unit is provided on an inner surface of the body 100 and an inner surface of the slider 200. The longitudinal sliding unit includes a driving motor 310 provided in the body 100, a pinion 320 coupled to the driving motor 310, and a rack 330 mounted longitudinally on the inner surface of the slider 200 and having one side engaged with the pinion 320. Reference numerals 201, 101, 230 and 130 represent guide grooves, guide protrusions inserted into the guide grooves, a receiver and a microphone, respectively. A semi-automatic closing technique may be implemented in the mobile terminal using a wire spring.
Referring to FIG. 3, operation of the mobile terminal is described. When a user talks to another party using the mobile terminal, the user first moves the slider 200 longitudinally to expose the keypad 110. The user then inputs the other party's telephone number by pressing the keys 111 and executes the call using the keys 221 on the operating keypad 220. After completing the call, the user moves the slider 200 longitudinally to cover the keypad 110. Furthermore, to answer a call, the user moves the slider 200 longitudinally to expose the keypad 110 and moves the slider 200 longitudinally to cover the keypad 110 when the call is completed.
Text messaging operates in a manner similar to voice calls. The user moves the slider 200 to expose the keypad 110 and types letters, numbers and/or symbols by pressing the number keys 111. Since the keys 111 on the number keypad 110 are primarily constructed for numerical input, each number may be entered with a single keystroke. However, to input letters or symbols requires the same key to be pressed two or three times.
Using the sliding type mobile terminal, the amount of space required for the slider 200 to move is minimal, allowing for the mobile terminal to have increased structural strength. On the other hand, in a folder type mobile terminal, the amount of space required for the folder to move is increased because the folder needs to be opened and closed on an axis located at one end of the body. Furthermore, the structural strength of the folding mobile terminal is weakened when the folder is opened.
However, in the top sliding type mobile terminal, the area on the body 100 that may be used for the keypad 110 is limited. Therefore, a small number of keys 111 are included in the keypad 110, necessitating that multiple functions must be assigned to each key 111. Furthermore, if letters are inputted using the keys 111, each key 111 must be pressed two or three times for each letter to be input. The above drawbacks may make the top sliding type mobile terminal inconvenient for sending and receiving text messages.